Başkent Üniversitesi Makaleler
Permanent URI for this collectionhttps://hdl.handle.net/11727/13096
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Item CTLA4 CT60 A/G Gene Polymorphism in Liver Transplant Recipients(Başkent Üniversitesi, 2010-09) Azarpira, Negar; Daraie, Masumeh; Aghdaie, Mahdokht Hosein; Malekhosseini, Seyed AliObjectives: Cytotoxic T-lymphocyte antigen 4 (CTLA4) has a critical role in the down-regulation of the immune response. We retrospectively examined the association between acute rejection and the single nucleotide polymorphism A/G in the CTLA-4 CT60 gene in liver transplant recipients. Materials and Methods: Fifty-one liver transplant recipients with at least 3 months’ follow-up were selected and genotyped for CTLA-4 CT60 polymorphism (HpyCH4 IV). The association of each genotype with allograft acute rejection was evaluated. Results: The mean age of patients was 27.9 ± 15.17 years (minimum, 1 year, maximum, 55 years), with 39% male and 61% female. Overall, 17 recipients (33.3%) experienced acute rejection within the first 3 months after a liver transplant. In our study, 50% of the patients (n=26) have G/A , 31% (n=16) have A/A, and 17% have G/G genotypes (n=9). Distribution of alleles was not different according to underlying liver disease. There also was no difference in sex, age, and distributions of CTLA-4 CT60 alleles with acute rejection episodes. Conclusions: CT60 A/G dimorphism within the 3'-UTR of CTLA4 gene does not influence acute rejection development in liver transplant. However, organ rejection is determined by a combination of several genetic traits rather than a single gene. Therefore, more studies with larger patient numbers are necessary to investigate the effect of combinations of genetic phenotypes involved in this process.Item Impact of Multislice Spiral Computed Tomography on Donor Selection and Surgical Planning in Living-Related Liver Transplant(Başkent Üniversitesi, 2010-06) Salama, Ibrahim Abdel Kader; Aal, Sayed Abdel; Korayem, Enas Mohamed; Dessouky, Basma Abdel MoneimObjectives: Living-donor liver transplant is used with increasing frequency to help compensate for the increasing shortage of deceased-donor liver grafts. However, donor safety is a primary concern, and selection of the preoperative imaging modality is important in preserving donor’s health by excluding unsuitable candidates, and tailoring the surgical procedure according to anatomic variations. In this study, we evaluate the impact of multislice spiral computed tomography on potential donor selection and surgical planning before living-related liver transplant. Materials and Methods: One-hundred seventy-five potential living-liver donors (62 women and 113 men; age range, 23-34 years; mean, 32 years) were included in our study. All subjects underwent multiphasic multislice spiral computed tomography. Postcontrast acquisitions were obtained for the arterial and venous phases. There were 139 potential donors for the right lobe and 36 potential donors for the left lateral segment. All data were analyzed to detect vascular variants, exclude focal liver lesions, and determine hepatic volume, and preoperative findings were correlated with intraoperative findings in 65 patients. Results: Of the 175 potential liver donors evaluated with multislice spiral computed tomography, 56 (32%) were excluded for the following reasons: portal vein anomalies in 11 (19.6%), hepatic venous anomalies in 9 (16.1%), fatty liver in 17 (30.3%), small liver volume in 12 (21.4%), and a focal lesion in the liver in 7 (12.5%). Of the 65 candidates, surgical planning and technique were modified in 24 donors and recipients, in 23 candidates, and the donor only in 1 candidate. Conclusions: Multislice spiral computed tomography provides parenchymal, vascular, and volumetric preoperative evaluation of potential donors for living-related liver transplant and has an effect on surgical planning: It allows the surgeon to reduce postoperative complications by modifying the surgical technique.Item Liver Transplant: A Primer(Başkent Üniversitesi, 2010-06) Movahedi, Zohreh; Saab, Sammy; Holt, Curtis D.Liver transplant has been accepted as a successful therapeutic option for patients with end-stage liver disease. Patient and graft survival has incrementally increased over the past 2 decades, mainly because of immunosuppressive regimens. However, the nonspecific nature of immunosuppressive agents is associated with an increased risk of development of opportunistic infections, renal impairment, metabolic derangements, neurotoxicity, de novo malignancies, and recurrence of the primary disease. Immunosuppressive regimen pharmacologic classes include calcineurin inhibitors, anti-metabolites, mTOR inhibitors, steroids, and antibody-based therapies. These agents affect T-cell–dependent B-cell activation, and target different sites in the T-cell activation cascade by inhibiting T-cell activation or causing T-cell depletion. The goals of immunosuppression in solid-organ transplant are to prevent allograft rejection as well as optimize allograft function, prolong patient survival, and improve patient quality of life. Therefore, it is essential to carefully select the immunosuppressive regimen that will result in significant improvements in long-term liver transplant patients’ survival and quality of life.Item Effect of Liver Transplant on Pulmonary Functions in Adult Patients with Alpha 1 Antitrypsin Deficiency: 7 Cases(Başkent Üniversitesi, 2010-03) Kashyap, Randeep; Orloff, Mark; Jain, Ashokkumar B.; Patil, Vrishali; Sheikh, Baber; Apostolakos, Michael; Ryan, CharlotteObjectives: Alpha 1 antitrypsin (A1A) is a 52 kD glycoprotein that is mainly synthesized in the liver. As a major protease inhibitor, it binds to and neutralizes neutrophil elastase, thereby limiting the damage to the normal tissues after an inflammatory response. A deficiency in A1A leads to end-stage liver disease, both in children and in adults. In addition, the deficiency also has a detrimental effect in the lungs of the adult population. Alpha 1 antitrypsin deficiency is corrected with hepatic replacement; however, the changes in pulmonary functions have not been studied before and after liver transplant. The purpose of this study was to observe the changes in the pulmonary functions of patients who underwent liver transplant for the treatment of A1A deficiency. Materials and Methods: Nine patients underwent liver transplant for A1A deficiency. Seven patients (5 men, 2 women; mean age, 49.95 ± 7.09 years) had their pulmonary function tests available before the liver transplant (mean, 5.6 ± 3.4; range, 0.9-10.1 months) and after the liver transplant (mean, 30.3 ± 18.4, range 7.8-48.1 months) for analysis. Results: The mean, preliver, transplant, FEV1 was 2.69 ± 0.9 L, which was nearly unchanged after the liver transplant to a mean of 2.7 ± 1.2 L. During the mean total interval of nearly 3 years, an estimated decline of 250 mL in FEV1 was expected. Conclusions: It appears from the results of our study that liver transplant probably prevented the progression of pulmonary disease in A1A-deficient patients. Further study and close, postliver, transplant follow-up is warranted to support our initial findings.Item Role of Ischemic Preconditioning in Liver Transplant: A Review of Literature(Başkent Üniversitesi, 2010-03) Macedo, Francisco Igor Bulcão; Miranda, Luiz Eduardo CorreiaInterruption of blood flow and subsequent organ reperfusion lead to significant tissue damage. This well-studied phenomenon is recognized as ischemia/reperfusion injury. Ischemic preconditioning refers to a mechanism in which a prior, short, ischemic period induces some protection against a subsequent prolonged ischemic and reperfusion damage. The mechanisms involved in ischemic preconditioning and its applications for clinical and basic research are discussed in this paper.Item Interventional Radiology in Liver Transplant(Başkent Üniversitesi, 2008-06) Boyvat, Fatih; Haberal, Mehmet; Karakayali, Hamdi; Aytekin, CuneytAn increased number of transplant centers now actively perform deceased-donor as well as living-related liver transplants. Although postoperative vascular and nonvascular complications after liver transplant have been well documented, early diagnosis and intervention are important to increase graft and recipient survival. With improvements in interventional radiologic techniques and a multidisciplinary approach to liver transplant, management of complications by percutaneous and endovascular techniques is possible with less morbidity and mortality. This article outlines the recent developments in, and applications of, interventional radiologic techniques in liver transplant patients.Item Lymphedema Tarda After Liver Transplantation: A Case Report and Review of the Literature(Başkent Üniversitesi, 2006-12) Saab, Sammy; Nguyen, Stephen; Collins, James; Kunder, Gregg; Busuttil, Ronald W.We present a patient with lymphedema that developed after orthotopic liver transplantation. The cause of the posttransplant lymphedema was likely related to a developmental abnormality of the lymphatic system that was exaggerated by refractory chylous ascites. A peritoneal fluid with a milky appearance, chylous ascites is rich in triglyceride and is caused by the obstruction or disruption of abdominal lymphatic channels. It is a rare complication that may develop after trauma or abdominal surgery or as a result of a malignant disease [1], and it is even more uncommon after liver transplantation [2]. Therapy for chylous ascites involves treating its underlying cause. In the patient we describe, lymphedema tarda, which was diagnosed 6 months after liver transplantation, was likely caused by chylous ascites and a developmental abnormality of the lymphatic system.Item Liver Resection and Transplantation in the Management of Hepatocellular Carcinoma: A Review(Başkent Üniversitesi, 2006-12) Kassahun, Woubet T.; Fangmann, Josef; Harms, Jens; Hauss, Johann; Bartels, MichaelHepatocellular carcinoma (HCC) accounts for more than 80% of all primary liver cancers and is one of the most common malignancies worldwide. Most patients with HCC also suffer from concomitant cirrhosis, which is the major clinical risk factor for hepatic cancer and results from alcoholism, infection with the hepatitis B or hepatitis C virus, and other causes. HCC is often diagnosed at an advanced stage, when established treatment options provide limited benefit. Effective treatment for HCC includes liver resection and liver transplantation. Under most clinical circumstances, those options provide a high rate of complete response and are thought to improve survival. Partial hepatectomy is the therapy of choice in patients with HCC and a noncirrhotic liver. Usually, liver transplantation is not indicated for such patients, although in individual cases, transplantation may be considered. For most cirrhotic patients who fulfill the Milan criteria, liver transplantation is the ultimate treatment option. Liver transplantation restores liver function and ensures the removal of all hepatic foci of tumor as well as tissue with a high oncogenic potential for early tumor recurrence. Because of the present lack of available organs, living-donor liver transplantation (LDLT) is an increasingly popular alternative. LDLT enables recipients to avoid a long pretransplantation waiting time and increases the number of livers available for transplantation. It is also the most effective approach to reducing the dropout rate. Strategies to reduce tumor growth in patients who are awaiting liver transplantation are important to ensure that those individuals continue to fulfill the Milan criteria for transplantation. For that purpose, using ablative techniques or chemoembolization to control local tumor growth is useful.Item Monitoring Human Cytomegalovirus (HCMV) in HCMV-Seropositive Orthotopic Liver-transplant Recipients by Means of Quantitative Real-time Polymerase Chain Reaction(Başkent Üniversitesi, 2006-12) Mengelle, Catherine; Abravanel-Legrand, Florence; Kamar, Nassim; Alain, Sophie; Basse, Grégoire; Pillet, Adèle; Lavayssière, Laurence; Suc, Bertrand; Izopet, Jacques; Rostaing, LionelObjective: Human Cytomegalovirus can be reactivated after orthotopic liver transplantation in patients who are seropositive for cytomegalovirus. Whether those cytomegalovirus-seropositive patients require immediate posttransplant (anti)cytomegalovirus prophylactic therapy or preemptive treatment as opposed to deferred treatment remains controversial. The aims of our study were to evaluate the relevance of cytomegalovirus monitoring with quantitative real-time polymerase chain reaction in whole blood and to analyze the factors that determine the treatment of the first episode of cytomegalovirus infection with intravenous ganciclovir in seropositive liver-transplant patients. Patients and Methods: Forty-two cytomegalovirus-seropositive liver-transplant patients were assessed for cytomegalovirus DNAemia every 2 weeks until posttransplant day 90 and every 3 to 4 weeks until day 180. Biochemical and hematologic parameters were also prospectively monitored. Results: Cytomegalovirus DNAemia was detected at least once in 27 patients (64%). Treatment was initiated in 12 patients (group 1) but not in 15 others (group 2). Median HCMV viral loads of the first positive and the highest DNAemia were statistically higher in group 1 than in group 2 (P = 0.01). Univariate analysis of DNAemia showed that alkaline phosphatase levels were significantly higher in group 1 than in group 2 (P = .0011) and that hemoglobin levels were significantly lower in group 1 than in group 2 (P = .0443). The results of multivariate analysis showed that the only factor that predicted the treatment of the first episode of HCMV DNAemia was a level of alkaline phosphatase greater than 150 IU/L [odds ratio, 20; range, 1.97-203.32; P = .01]. Conclusions: A combination of criteria, including viral-load kinetics, clinical factors, alkaline phosphatase levels (in particular), and the patient’s immune condition, is required to efficiently monitor patients who are seropositive for cytomegalovirus after orthotopic liver transplantation.Item Determinants of Fasting Total Serum Homocysteine Levels in Liver Transplant Recipients(Başkent Üniversitesi, 2006-06) Akoglu, Bora; Wondra, Kathrin; Caspary, Wolfgang F.; Dominik, FaustObjectives: Homocysteine (HCY) is a sulfur-containing amino acid considered to be a marker for a relative folate deficiency. Hyperhomocysteinemia is a known risk factor for development of cardiovascular disease, vascular dementia, depression, and possibly some carcinogeneses. Liver transplant recipients have an increased risk for cardiovascular disease because of a high incidence of obesity, arterial hypertension, diabetes mellitus, and hyperlipidemia. The aim of this study is to elucidate the determinants for hyperhomocysteinemia as an additional risk factor in these patients. Materials and Methods: Seventy stable liver transplant recipients, 48 men (mean age, 50 ± 11 years) and 22 women (mean age, 52 ± 13 years) had their serum homocysteine levels tested after orthotopic liver transplantation. For mainstay immunosuppression, 53 patients were treated with tacrolimus, 10 with cyclosporine, 3 with mycophenolate mofetil, and 4 with sirolimus. Fasting blood samples were obtained and analyzed immediately (within 1 hour) for total serum homocysteine by high-performance liquid chromatography. Results: In all patients, mean homocysteine levels were 22.7 ± 14 µmol/L (normal range, 9-15 µmol/L). Forty-six patients were found to have homocysteine levels > 15 µmol/L, and all 70 recipients had homocysteine levels > 9 µmol/mL. In our patients, increased homocysteine levels correlated well with body mass index and renal function. Homocysteine levels in patients receiving cyclosporine were higher than those in patients receiving tacrolimus (22.3 ± 6 vs 17.9 ± 12 µmol/L, P < .05). Conclusions: Overall, homocysteine levels are significantly increased in liver transplant recipients. Homocysteine levels correlate well with obesity, renal function, and the particular immunosuppressant protocol. Therefore, a specific treatment for patients after liver transplantation (eg, one with folates) might reduce the risk of complications resulting from hyperhomocysteinemia.